3, 20-diacyloxy-5, 7, 9 (11), 17 (20)-pregnatetraene adducts



Patented Jan. 13, 1953 UNITED STATES OFFICE 3,20-DIACYLOXY-;7,9 (11) ,17(20 PREGNATETRAENE ADDUCTS Robert H. Levin, A Vern McIntosh, Jr., and?George B. Spero, Kalamazoo, Mich., assignors! to The Upjohn Company,-Kalamazoo, Mich., a

corporation of Michigan No-Drawing; Application September 9, 1950,SerialsNo. 184,111

fi Claimsi 1 The present invention relates to adducts of?3,20-diacyloxy- 5,7,9 l ,l 7( 20) pregnatetra'enes' with certaindienophilicanhydrides andest'ers; and to a process for the productionthereof. This application is a continuation-in-part' of" our prior-filedcopending application Serial" 121,224; filed October 13, I949.

The compounds of the presentinvention may be represented by thestructural formula:

AcO'

Wherein-Ac is the residue ofan organic carboxylic" acid,,especially suchacids containing from one to eight carbon atoms, inclusive; and A-is'anad duct radical derived from a dienophile selected from the groupconsisting of maleic anhydride' and maleic acid diesters containing fromone to eight carbon atoms, inclusive, inthe esteriiy--=- ing group.

It is an object of thepresent invention to'=pr'o-'- vide a novel groupof compounds which are-use-"- ful in the preparation of-steroidcompounds con-- taining an oxygen atom at carbon atom eleven;- Anotherobject of the invention is-the provision of a process for theproductionof the novel com pounds, adductsof 3,20-diacyloxy-5,7,9(11),--17(20) -pregnatetraenes; Other objects of" the invention willbecomeapparenthereinafterr- The compounds of the present invention, as

previously stated, are useful in the preparation' of steroid compoundshaving an oxygen atom at tached to carbon atom-eleven; Such compoundsareof particular interest'in the filed of steroid research due to thebiological-activity of the corti-' cal hormones and certain knownderivatives thereof, whichoxygenatedsteroids are' known -tohavebiological effects difiering' markedly from theiunoxygenated steroids.It is, therefore, -.o-i'

importance to investigate theoxygenated derivaa tives of. such. adducts,particularly thoseoxy genated at carbon atom eleven, as well'- as.toinvestigate the biological activity of the. adducts themselves andtheir transformation products; The importance of such investigation-ismore-@- over emphasized by the acute shortagecof adrenal: corticalhormones, and the absence of any pres;- ent suggestion for alleviationof the'said' short-; age except through organic synthesis.

Novel compounds of, therpresent .inven-tion 2 which-are of-particularinterest are= those com pounds of the above generic formula whereinAcrepresentsthe' residue of a carboxylic acumen-- taining up to andincluding eight carbon "atoms: Among the acidswhich can be used are"formic; acetic, propionic, butyric; valeric, hexanoic; heptanoic,"oetanoic,'- succinic, glutar-ic, cyclo-'- pentanoic, benzoic, toluic;and the like. Pieferred acidsare the lower-aliphatic acids; Theacidsma-y also contain substituents; such as I ia-lot alkyl; andmethox-y; which are non reactive un der thereactionconditions employed.The adduct bridge (-'--A- in -suchcompound's may be represented by thegraphic formulae which is representative oi? the maleic anhydrideadduct.

The compounds of the invention are usually colorless crystalline solidswhich are soluble in ether, halogenated hydrocarbons, acetone, ethylacetate, and b'enzene.- The anhydrides are' readily converted-into:(118858! adducts'* by estetification with conventional reagentssuch-as-Lth'e diazoalkanesr [Wilds :et al.', J .4 Org. Chem: 113;,-7.63: (1948):];

The 3,20-diacyloxy-5, 7,9 (11) ,17 (20) -pregr;iatetew- 3 raene adductsof the present invention have the formula:

AcO

wherein A is an adduct radical derived from a dienophile selected fromthe group consisting of maleic acid anhydride and maleic acid diesters,and wherein A is an acyloxy group. These compounds are convenientlyprepared by heating the corresponding 3-hydroxyor 3-acyloxy- 5,7,9(1l)-pregnatrien-20-one maleic acid, maleic acid anhydride, or maleic acidester adduct with a large excess of an organic carboxylic acid anhydridein the presence of a small amount of para-toluene sulfonic acid. Themixture is heated at the boiling point of the anhydride until theanhydride is nearly completely removed, which usually requires aboutfour hours when the amount of anhydride employed is about 150milliliters, but which will vary with the amount of anhydride used. Thepreferred anhydride is acetic anhydride, but other anhydrides, such aspropionic, butyric, valeric, hexanoic, heptanoic, and octanoicanhydrides, as well as benzoic acid anhydride, ortho-toluic acidanhydride, and the like are also operative. The acid anhydrides can alsobe substituted by non-reactive groups, such as halo, alkyl, and methoxy,as in the case of chloroacetic, ortho-toluic, or methoxybenzoic .acidanhydrides. If a 3-hydroxy 20-keto adduct is thus reacted with ananhydride, the hydroxy group is usually acylated, and, similarly, if amaleic acid adduct is used instead of a diester or an anhydride, theanhydride will be formed. The

enol ester can be isolated by carefully decomposing the residue afterdistillation of the anhydride with water and filtering off the solidester, which product can be further purified by recrystallization fromacetone-water, alcohol, or like solvents, if desired.

The 3-acy1oxy-5,7,9(11) -pregnatrien-20-one adducts are convenientlyprepared by the selective oxidation of an enol ester of an adduct of 3-acyloxybisnor-5,7,9(11) -cholatrien-22-al, represented by the formula:

AcO

formula: V

CH-CHO wherein A and Ac have the values previously given, to the actionof an acid anhydride or an acid halide in the presence of an alkali saltof the acid. The adducts of 3-acyloxybisn0r-5,7,9(11)- cholatrien-22-alscan be prepared from adducts of 3-esters of dehydroergosterol byselective oxidation as described and claimed in the copendingapplication Serial 111,100 of Robert H. Levin, filed August 18, 1949,and as more fully described hereinafter.

The 3-esters of dehydroergosterol, from which the 3 acyloxybisnor5,7,9(11) cholatrien 22- al adducts are prepared, can be synthesized inseveral Ways starting with ergosterol. For example, ergosterol can betransformed to dehydroergosterol with mercuric acetate according toknown methods [Windaus et al., Ann. 465, 157 (1928)] and the 3-hydroxygroup of the dehydroergosterol acylated by known procedure. A1-ternatively the 3-hydroxy group of ergosterol can be acylated prior tothe preparation of the dehydro derivative, a procedure which isparticularly preferred in the preparation of the 3- acetoxy derivative.The adducts of dehydroergosterol are then prepared by the addition ofmaleic anhydride or the like to dehydroergosterol or a 3-ester thereofaccording to known methods EHQnigmann, Ann. 508, 89 (1934) Theanhydrides can then be converted to their corresponding acids and estersif desired.

The ester group, when present in the 3-position of dehydroergosterol, isfor the purpose of protecting the 3-hydroxy group in subsequent chemicalreactions. For this purpose any convenient ester of an organiccarboxylic acid, which is non-reactive under the conditions of thereaction, is suitable. The preferred acids are the fatty acids such asformic, acetic, propionic, butyric, valeric, hexanoic, heptanoic,octanoic; dibasic acids such as malonic, succinic, phthalic;cycloaliphatic acids such as cyclopentanoic and cyclohexanoic; andaromatic acids such as benzoic, toluic, and the like. The acids may alsocontain substituents such as halogen, alkyl, the

methoxy radical, and the like, and these substituents will be carriedthroughout the synthesis. If desired, the acyl group can be changed toanother acyl group by saponifying the ester to give a B-hydroxycompound, which can then be re-esterified as previously described.

A preferred method for preparing some of the dehydroergosteryl adductscomprises the saponification of a S-acyloxy-adduct of dehydroergos-.terol with dilute alkali followed by acidification.

diazoalkane [Wilds et.al., J-.. Org Chem. 13; 763

(1948) l, e. g., diazomethane, diazoethanadiazobutane, and the like,

The selective oxidation, of an adduct of dehy-r.

droergos'terol, or a 3-ester thereof, to produce an ductv of, 8,- d oy-bisnor-53,90 -cho jatr.ie 2-a .v o a. 3- s er h reo s accomp ished bdissolving the dehydroergosteryl adduct in a,

itab nt. cool n o. abo minu 8. o pl s. 30 degrees centigrade, andpassing ozone into thesolution until about, 1,0 to' 1,2,5 m le oi ozoneper, mole, of adduct haye been absorbed. The, temperature of thesolutionshould be main:

tained below plus 30 degrees centigrade, prefer ably between atemperature of minus 30 and minus -'70 degreescentigrade, duringtheaddition of ozone, although temperatures as low as-minus n s igh s lu 3-degrs s ent s dssm operative. The lower temperatures of the pre:

ferred range. are readily'obtainedhy coolingthe solution 'of'the adductwithabath of solid car-Q hon i ide. n b io e drihsl' ika. i bii livarious other methods of cooling canbe used Many oi the'customarysolvents used in ozoniza tions. such as chloroform, aceticacid, carbon tetrachloride, ethylene. chloride, illethylene chloff Theozonides are then decomposed under-re;

ducing conditions, that is, in the absenc eiot o i-., dizing'agents,whether added or formed the course of the reactionby productsofdecomposition of the ozonide. This means that excess oxy-v gen formed bydecomposition of the] ozonide is prevented from forming hydrogenperoxide. by. combining with any moisture present, and that molecularoxygen isprevented from oxidizinggthc,

aldehyde thus formed. This can beconveniently accomplished bydecomposingthe ozonide in glacial acetic acid by the addition of finelypowderedzinc.

As is conventional with ozonizations. when conducted in solvents, otherthan glacial acetic acid,

the solvent used for ozonization is replaced, after completion of theozonization, by adding glacial acetic acid and removing thelower-boiling sol-.

vent by fractional distillation. Alternatively, the v solvent can beremovedby careful warming underreduced pressure prior to the addition ofglacial acetic acid, if desired,

A r o p sit on f h snids. am n conventional manner, such as by formationof an aldehyde derivative, e. g., the dinitrophenylhydrazone.

be conveniently prepared by heating the. corressp d s yd o 3aoxy.aldehyde mal c aciamaleic. ci n dr e, or ma ei a id; t r

adduct Withv a large, excess. of an .organic carboxylic. acid anhydridein the presence. of a small;

oi a1. hsz n the aldehy e. tan saecovered, 0

by diluting the acetic acid with water;, orin other h i-r s nlan-becpnren' ntly fellows y obs.

serving the-color chan es he reac io optimum yi s. bein Qht ed by: sconthe application of heat when the color Oifthg s lution; chan es. tram.yellow o. brown-. Q dir ees; .n isradermu tib i sin s othe wis tends gdemrose t e'h sher-tsmr eratu e I .1. td r i xr dehyde-a duet... s h sitactsq-w thnan '.-thQ h i x r roup. ill. ea r d. n im arlnii a eio. acidadduct is used instead of, a diester or an nh dride... he anhydride;wille.- or erle The; 01. e tensanb salats lbr mw nsthe e as anhydrideunder reduced pressure and separ e, e q ster f om, alka i.mst lsa st h hB clure eld a pr d ct a ifi i .ht pii a o mast purp tbutwh sh a utih r1-uh fi 1i.by. recrystallization from acetone-water, acetonepentane, orlike solvents, if desired.

The ozonization of the thus-prepared-enol acylate, to; produoea3=a0Y1QXYr5 7 .9E ;.1) :nregna rienr 20:.one adduct; involv s dissolyns:.. ha ,e ol s. r: in. a. suitable. solvent; oolin to, about.ishtywdesrees oentisra eto. plus thirty de ree-s2, centigrade, and;passin ozone. zonized 11113- 31 ozonizedoxy en. into the-solution until.about .0... to about. 1.25. moles: preferably ..0-to. .1.;mo,,. of,ozone .per mole. of; adducthave. been ,absor ecli. The additionof ozone;to the. 2 1: 2 .dollblebqndl. i so. r p that only. asmall, amount of;ozona escapes from the reaction mixture, and the; amount of ozoneordinarily required therefore closely approximates thev theoreticalamount. Loss to the solvent, if any loss occurs, must be taken intoconsideration in calculating the amount of ozone to be'introduced. Thetemperatureof the solution should be maintained. below-1 plus thirtydegrees centi-grade, preferably-betweena temperature of-minus thirty andminus seventydegrees centigrade, during the addition-ofozone, althoughtcmperaturesas low as minus eighty and as high as plusthirty degrees,centigrade are operative, The lower temperatures of the ils e rs realy, a isdi 990m 1 h? Q Q JiOB. of thsadsiuct. witna .bathntso d .carbndioxid in acetone, or. the like, although various other methods oijcooling may be employed. Many of, e ustomary so reni use i. onizs nsltich ch orof m .m t s-s lori a eth lene ch1 ride, carbon tetrachloride,acetic acid, and the like, can be used for the ozonization reaction. I

The 20:22 ozonides thus produced arethen decomposed under conditionsnormally employed for decomposition of such compounds, This can qnv ii eybe ac omp ishe vec m o nsthe ozonide ,vs/ith' hydrogcn..peroxide, byhydrolysis, with zinc glacial acetic acid, or by a.,catalyticamountofcolloidal metalsuch as silver, platinum, or palladium in a solvent. suchas glac'ia l acetic. v acid, alcohohor ethyl acetate, in which lattercase reductive conditions, e. g., a,hydrogen at- Q Phe aa sos p o d; he.useof f TQ uQrt ve ond ons. is, well establishedi 1 [Hill and Kelly,Organic Chemistry, page.,- .53,:. The .-.B;1akiston; CompanyPhiladelphia. (1934),;- Church,et..al;,.. J..: Am. Chem. Soot. 55;rifle-18M 7 (1934); Gilman "Organic Chemistry," Second Edition, page636, John Wiley and Sons, New York (1943); Long, Chem. Reviews 27,452-454 (1940)].

As is conventional with decomposition of ozonides with zinc, when theozonizations are conducted in solvents other than glacial acetic acid,the solvent used for the ozonization is replaced, after completion ofthe ozonization, by adding glacial acetic acid and removing thelower-boiling solvent by fractional distillation, or the solvent can beremoved by careful warming under reduced pressure prior to the additionof acetic acid, if desired. After decomposition of the 20:22 ozonide andremoval of the metal, the ketone can be recovered by diluting the aceticacid with water, or by other conventional procedure for the recovery ofketones, such as by formation of a carbonyl derivative, e. g., the2,4-dinitrophenylhydrazone. Recrystallization from acetone or the likeresults in a more highly purified ketone product.

The following examples are illustrative of the process and products ofthe present invention, but are not to be construed as limiting.

PREPARATION l.-DIMETHYL MALsA'r-E Annuo'r or DEHYDROERGOSTEBYL BENZOATEPREPARATION 5.1\[ALEIC ANHYnmoE Aoooc'r or'3-HEPTANOYLOXYDEHYDBOERGOSTEROL 191.5 degrees centigrade.

To a solution of 21 grams of dimethyl maleate adduct ofdehydroergosterol in 69 milliliters of warm pyridine was added 9.5milliliters of benzoyl chloride. After standing at room temperature forfifteen minutes, the mixture was poured into 1400 milliliters ofice-water and the solid removed by filtration, dried, and recrystallizedfrom acetone. There was thus obtained 26.4 grams of dimethyl maleateadduct of dehydroergosteryl benzoate, melting at 203 to 205.5 degreescentigrade.

PREPARATION 2.DIMETHYL MALEATE ADDUOT or DEHYDBOERGOSTERYL ACETATE In amanner esentially that described in Preparation 1, the dimethyl maleateadduct of dehydroergosteryl acetate, melting at 177 to 179 degreescentigrade, was prepared from the dimethyl maleate adduct ofdehydroergosterol and acetyl chloride.

PREPARATION 3.DIMETHYL lilALEATE Annucr or DEHYDROERGOSTERYL FORMATE Asolution'of six grams of dimethyl maleate adduct of dehydroergosterol infifty milliliters of 87 per cent formic acid was heated under reflux forone hour, cooled, and the dimethyl maleate adduct of dehydroergosterylformate filtered therefrom. Upon crystallization from acetone, thepurified material melted at 177.5 to 178.5 degrees centigrade.

PREPARATION 4.MALEIO Acre ADDUGT or DEHYDROERGOSTEROL A solution of 2.0grams of sodium hydroxide in twenty milliliters of water was added to asolution of 1.73 grams of the maleic anhydride adductOf'dGhYdIOBIgOStBI'YI acetate (M. P. 230-232 degrees centigrade) inforty milliliters of dioxane. The mixture solidified, but dissolved onaddition of 300 milliliters of water and heating to eighty degreescentigrade. After half an hour the solution was cooled and made acidwith aqueous three normal hydrochloric acid, to give 1.61 grams ofprecipitate. On crystallization from a dioxanewater mixture, the maleicacid adduct of dehydroergosterol melted at 190-192 degrees centigrade.

PREPARATION 6.MALEIo ANHYDBIDE ADDUCT or 3- BETAACETOXYBISNOR 5,7,9 (11)-GHOLATBIEN-22-AL A solution of 5.35 grams of the maleic anhydrideadduct of 3beta-acetoxydehydroergosterol in 107 milliliters of methylenechloride was cooled to about minus seventy degrees centigrade andozonized until 505 milligrams of ozone had been absorbed. Thetemperature of the solution was then gradually raised to about plus tento fifteen degrees centigrade, whereupon seventy milliliters of glacialacetic acid was added and the methylene chloride removed under reducedpressure. Seven grams of zinc dust was then added to the cold solutionat a uniform rate over a period of ten minutes, while keeping thereaction temperature below plus twenty degrees centigrade. After beingstirred for fifteen minutes, the mixture was filtered and the filtratepoured into water. There was thus obtained 4.31 grams of maleicanhydride adduct of 3-beta-acetoxybisnor-5,7 ,9 (11) -cholatrien-22-al,a fine white powder which melted at 187-197 degrees centigrade.

To a solution of 0.30 gram of the maleic anhydride adduct of3-betaacetoxybisnor-5,7,9(ll)- cholatrien-22-al, in thirty millilitersof ethanol, was added twenty milliliters of alcohol containing onepercent 2,4dinitrophenylhydrazine and three percent concentratedhydrochloric acid. The mixture was allowed to stand for one hour at roomtemperature and then placed in a refrigerator to complete precipitationof the yellow crystals. The precipitate was then collected andrecrystallized from a mixture of chloroform and alcohol, to give the2,4-dinitrophenylhydrazone of the maleic anhydride adduct ofB-beta-acetoxybisnor-5,7,9(11) -cholatrien-22-al, melting at 269- 271degrees centigrade.

PREPARATION BnTA-AcEToxYBIsNoR-5,7 ,9 (11) -CHOLATRIEN-22-AL Atwo-liter, round-bottom flask was charged with fifty grams (0.93 mole)of dehydroergosteryl acetate maleic anhydride adduct and one liter ofmethylene chloride. The solution was cooled to Dry-Ice temperature witha trichloroethylene bath and ozonized oxygen passed through at a rate of1200 milliliters of oxygen per minute (at this rate the ozonizer wasproducing about 36 milligrams of ozone per minute). The flow of czonizedoxygen wa maintained for 128 minutes, a total of 4608 milligramspercent) of ozone being passed into the solution. The reaction mixturewas transferred to a two-liter, round-bottom flask fitted with acapillary and a condenser for downward distillation, 300 milliliters ofacetic acid added, and the methylene chloride distilled over in vacuo atforty degrees centigrade or below. The flask was then placed in a waterbath and fitted with a stirrer. An additional 200 milli- .liters ofacetic acid was added and the ozonide (.-I\IALEIO ANHYDRIDE Aonucrr or3- decomposed by the addition of fifty grams of zinc dust. The zinc dustwas added in portions over a period of twenty to thirty minutes whilethe solution was stirred and the temperature maintained at seventeen totwenty degrees centigrade. After addition, the mixture was stirred foranother twenty minutes and then filtered. The precipitated zinc dust waswashed by filtering 100 milliliters of acetic acid therethrough, and thefiltrate gradually diluted with water (1100 to 1200 milliliters) untilthe product had been drowned out. The product was then cooled in therefrigerator overnight and filtered. The yield of crystalline productwas 42 grams, assaying 89- 95 percent of the desired aldehyde.

PREPARATION 8 In a manner essentially that described in Preparation 6,the following compounds were prepared:

(1) 'Mal'eic anhydride adduct of3-beta-formoxybisnor-5,7,9(11)-cholatrien-22-al, melting at 95-130degrees centigrade. 2,4-dinitrophenylhydrazone, melting at 165-168degrees centigrade.

(2) Maleic anhydride adduct of 3-beta-heptanoyloxybisnor 5.7,9(11)-cholatrien 22 a1, melting at 197.5-199 degrees Centigrade. 2,4-dinitrophenylhydrazone, melting at 253-257 degrees centigrade.

(3) Dimethyl maleate adduct of 3-beta-benzoyl- "oxybisnor-5,7,9 11)-cholatrien-22-al, melting at 183-187 degrees Centigrade.2,4-dinitrophenylhydrazone, melting at 224-249 degrees centigrade.

(4) Dimethyl maleate adduct of B-beta-aceto'xybisnor-5,7,9(11)-cholatrien-22-a1, melting at 172-178 degrees centigrade. 2,4-dnitrophenylhydrazone melting at 238 to 244 degrees centigrade.

(5) Dimethyl maleate adduct of 3-hydroxybisno'r-5,7,9(11)-cholatrien-22-al, melting at 163-170 degrees centigrade.2,4-dinitrophenylhydrazone, melting at 250-254 degrees centigrade.

In a manner similar to the above, the maleic anhv iride adduct of3-hydroxybisnor-5.'7;9(11)- chlatrien-22-al is obtained from'dehydroergosteryl malec anhydride adduct; the maleic acid adduct of3-hydroXybisnor-5.7.9(11)-eholatrien- 22-al is obtained from dehvdroerostervl maleic acid adduct: and 3-acvloxvhisnor-5.'7.9(11)-cholatrien-22-al maleic acid add cts are obtained from the maleic -aci-dadduct B-acyloxydehydroe'rgosterols.

P EPARATION 9. D''riinc'r'nYnlVIALEA'rE Annuor 0F 3-HYnRoxYBIsNoR-5,7,9(11) -cHoLATarEN-22-AL A solution of 2.69 grams (.005 mole) of thedimethyl ester of the maleic acid adduct of dehydrcergosterol, in eightymilliliters of methylene chloride, cooled by a Drv-Ice and 'trichloroethlene bath was treated with ozonized oxygen until 247.36 milligrams(.0051 mole) of ozone was absorbed. The solution was then allowed 'towarm to room temperature, whereafter thirty milliliters of acetic acidWas added and the methylene chloride removed in vacuo. While cooling ina water-bath at fifteen degrees centigrade, four grams of zinc dust wasadded in portions with stirring, the temperature being maintainedbetween fifteen and twenty degrees centigrade. Stirring was continuedfor another fifteen minutes, whereafter the zinc was separated byfiltration. The filtrate was diluted with water 10 to cloudiness,extracted with ether, the ether extract washed with sodium bicarbonateand then with water to neutrality, the solution then dried A mixture oftwenty grams of the maleic anhydride adduct of3-beta-acetoxybisnor-5,7,9 (11) 'chola'trien-22-al, six grams ofanhydrous sodium acetate, and 600 milliliters of acetic anhydride, washeated under reflux for six hours, whereafter volatile components wereremoved under reduced pressure. The resulting solid was digested withfivefifty-milliliter portions of boiling acetone for five minutes each,and the extracts combined-and diluted with 130 milliliters of water.There was thus obtained sixteen grams of the maleic anhydride adduct of3-beta-acetoxy-22-acetoxybisnor '5,7,9 (11.),20(22) cholatetraene, whichmelted at 186 'to 193 degrees centigrade. Re-

crystallization of the crude product from a mixture of acetone andpen-tane raised the melting point to 200.5 to 202 degrees centigrade.

"PREPAR'A r'ION '11 In a manner essentially that described inPreparation 10, the following compounds were prepared:

(1) The dimethyl maleate adduct of a-betabenfzoyloxy--22-aceto'xbisnor-5,7,9(11) ,20'(2'2) circlat'etraene, which melted "at "210 to211' degrees centigrade (2) The dimethyl maleate adduct of 3-betaacetoxy22 acetoxybisnor 5,7,9(11).,20(22)'- cholatetraene, which melted at 181to 183 degrees centigrade In the same manner as given above,-22-acyloxy,

e. g., formoxy, 'acetoxy, propionoxy, butyroxy,

valeroxy, hexanoyloxy, heptanoyloxy, octanoyloxy, 'benzoylox'y,'naphtl'ioyloxy, and the like 3 acyloxybisnor 5,7,9( 1 1) ,2'0 (22)-cholatetraene 'adduct's, are obtained from the compounds ofPreparations '6, '7, and '8. Such representative compounds include3-formoxy-22-acetoxybisnor- 5,7,9 (11) ,20(22) cholatetraene, 3propi'onoxy- 22 acetoxybisnor 517,9(11) ,20(22) chola'tetraene, 3,22dipropionoxybisnor- 5,7,9( 11) ,20'( 22') chol'atetr'aene, 3,22dib'enzo'yloxybisnor 5,7,9-

(11') ,20 (22) -cholatetra'ene, and 3-heptanoyloxy- 22cctano'yloxybis'nor 517,9(11) ,2'0'( 22 cho'lat'etr'ae'ne adducts'withinaleic anhydride or'maleic acid esters such as the dimethylmale'ate,diethyl maleate, dipropyl maleate, diisopropyl maleate, dibutyl maleate,diocytl maleate, dibenzy1 malea'te,'and the like.

PREPARATION 12;-MALEIC ANHYDRIDE- Aonocrr or 3-'BETA-ACETOXY-5,-7 ,9 11)--PREGNATBIEN-2O-0NE A solution of 5.08 grams of the maleic anhydrideadduct of 3-beta-acetoxybisncr 5,7,-

9(11)-cholatrien-22al enol acetate in mil1icentigrade.

, ii liters of methylene chloride was cooled to about minus seventydegrees centigrade and ozonized 'until 483 milligrams of ozone had beenabsorbed.

Fifty milliliters of glacial acetic acid was then added and themethylene chloride removed under reduced pressure. An additional thirtymilliliters .of glacial acetic acid was then added and the .The mixturewas stirred for an additional twenty .minutes, filtered, and the zincwashed with 140 milliliters of glacial acetic acid. The organic extractswere combined and diluted with seventy milliliters of water. Whencrystallization commenced, the rate of precipitation was increased byaddition of two volumes of water. There was thus obtained 4.0 grams ofthe fnaleic anhydride adduct of 3-beta-acetoxy-5,7,9(11) -pregnatrien-20-one, which melted at 240 to 264.5 degrees centigrade.

PREPARATION 13.MALEIC Aom Annnor or 8-3pm- HYnRoxY-5.7.9 (11)-PREGNATRlEN-20-ONE A solution of 4.52 grams (0.0100 mole) of the maleicanhydride adduct of 3-beta-acetoxy- 5,7 9(11) -nregnatrien-20-one, M.1?. 263-2645 degrees centigrade, in a mixture of 100 milliliters of1,4-dioxane and 400 milliliters of water containing four grams (0.10mole) of sodium hydroxide was allowed to stand at room temperature fortwo and one-half hours. whereupon a small quantity of plate-likecrystals formed. These were dissolved by heating the mixture to seventydegrees centigrade for one-half hour. The reaction mixture was then madeacid with fifty milliliters of three normal hydrochloric acid andrefrigerated to give a precipitate of 3.05 grams of needlelike crystalsmelting at 173-177 degrees centigrade. On crystallization from adioxane-water mixture, the compound melted at 211-215 degrees Themelting point was found to vary somewhat with the rate of heating.

"Analysis:

A suspension oi 0.400 gram of the maleic acid adduct of3-beta-hydroxy-5,7,9(1l) -pregnatrien- 20-one, in fifty milliliters ofdry ether, was cooled in an ice-salt bath while a slight excess ofdiazomethane in methylene chloride was added over a 25 minute periodwith stirring. Ten minutes after addition was complete, the solution wasplaced on a steam bath and concentrated rapidly to dryness. The residuewas crystallized from an acetone-water mixture to give 034 gram of thedimethyl maleate of 3-beta-hydroxy-5,7,9(1l)- pregnatrien-20-one,melting at 193-195 degrees centigrade. After chromatography andrecrystallization, the compound melted at 192-197 degrees centigrade.

In the same manner as given above, other dialkyl maleates, e. g., thediethyl, dipropyl, diisopropyl, dibutyl and dioctyl maleates of3-hydroxy-5,7,9(1l) -pregnatrien-20-one are prepared frm-3-hydroxy-5,7,9(11) -pregnatrien 20 one maleic acid adduct and theappropriate dia zoalkane, or by other equivalent esterificatlonprocedure.

5,7,9(11) dimethyl Prmmm'rron 15.DmarHYr. MALEATE or 3-min-AcaroxY-5,7,9 (11) -PREGNATBlEN-20-ONE A solution of 0.15 gram of thedimethyl maleate adduct of 3-beta-hydroxy-5,7,9 (11) -pregnatrien-20-one, in 2.5 milliliters of acetic anhydride and 2.5 milliliters ofpyridine, was heated on the steam bath for ninety minutes, cooled toroom temperature, and poured into ice-water. The resulting precipitatewas collected by filtration and found to melt at 205-209 degreescentigrade. Recrystallization from methanol gave the dimethyl maleate of3-beta-acetoxy-5,7,9(l1) -pregnatrien- 20-one, melting at 207-211degrees centigrade.

Analysis:

Calculated for CzeHssOv--- C, 69.86; H, 7.68 Found 69.81 7.86 69.70 7.62

By the same manner of esterification, the following C-3 esters wereprepared: (1) dimethyl maleate adduct of 3-beta-formoxy-5,7,9(l1)-pregnatrien-ZO-one, melting point 223-230 degrees centigrade, and (2)the dimethyl maleate adduct of 3-beta-benzoyloxy-5,7,9 (11)-pregnatrien-20- one, melting point 250-254 degrees centigrade.

PREPARATION 16.MALEIC ANHYDKIDE ADDUCT or 3- BETA-HEPTANOYLOXY-5,7 ,9(11) rmzenarmnnQO-ona The maleic anhydride adduct of3-beta-heptanoyloxy-5,7,9(11) -pregnatrien-20-one, melting point -171degrees centigrade, was prepared by refluxing the maleic acid adduct oi3-betahydroxy-5,7,9(1l) -pregnatrien-20-one with heptylic anhydride andpyridine for a period of twenty hours, and working up the reactionproduct in the usual manner.

PREPARATION 17.HALEI0 ANHYDBIDE Annno'r or 3 BETA-HYDBOXY-5,7,9 (11)-PREGNATBIEN-20-ONE Similarly, the maleic anhydride adduct of 3- .betahydroxy 5,7,9(11) -pregnatrien'- 20 one,

melting point about degrees centigrade, was prepared by refluxing themaleic acid adduct of 3-beta-hydroxy 5,7,9(11) -pregnatrien 20 one withDowtherm for eight hours. The 3-hydroxymaleic anhydride adduct is alsoobtained by heating the 3-hydroxy maleic acid adduct to just above itsmelting point, which procedure causes Water to be evolved, with theclosing of the anhydride ring.

In the same manner as given above, still other 5,7,9(11)-pregnatrien20one adducts are pre pared from the corresponding3,22-diacyloxybisnor 5,7,9(11),20(22) cholatetraene maleic acid, maleicacid anhydride, and maleic acid diester adducts. Such compounds includethe 3- formoxy 5,7,9 (11) pregnatrien 20 one maleic acid, maleic acidanhydride, dimethyl maleate, diethyl maleate, dibutyl maleate, dioctylmaleate, diisopropyl maleate, dibenzyl maleate, and like adducts; thecorresponding 3-propionoxy, butyroxy, valeroxy, hexanoyloxy,heptanoyloxy, 0ctanoyloxy, naphthoyloxy, benzoyloxy, and similar20-ketone adducts, including, for example, 3- propionoxy-5,7,9(11)-pregnatrien-20-one dipropyl maleate, 3-benzoyloXy-5,7,9 l1)-pregnatrien- 20 one dibenzoyl maleate, 3 heptanoyloxymaleate, 3valeroyloxy- 5,7,9(11)-pregnatrien-20-one maleic acid anhydride adducts,and the like.

Example 1.Maleic anhydride adduct of 3-be'ta- 20-diacet0my-5,7,9 (11) ,17 (20) -pregnatetraene A solution of 2.25 grams (.005 mole) of themaleic anhydride adduct of 3-beta-acetoxy- 5,7,9(11)-pregnatrien-20-oneand 0.95 gram of 13 p-toluenesulfonic acid in 150 milliliters of aceticanhydride-was distilled slowly for four hours, at the end of whichperiod the twenty milliliters of acetic anhydride which remained wasremoved in vacuo. The residue was dissolved in ether, washed with fivepercentsodium bicarbonate and water, dried, and evaporated to dryness.The crude dark product was treated with Darco activated carbon andcrystallized from alcohol to .give- 016 gram of crystalline maleicanhydride adduct of 3-beta-2il-diacetoxy-5fl ,9-(11) .17 (20)pregnatetraene, melting at 195 to 217 degrees centigrade. After severalrecrystallizations. from methanol, it melted at 217.5-219degreescentirade.

Analysis:

Calculated for C29II3407 C, 70A2; H, 6.93 Found 70.54 7.05

Example 2.Dimethyl maleate adduct 3-beta,- 20-diacetoxy-5,7,9 (11) ,17(20) -pregnatetmene A 50'D-milliliter round-bottom flask, fitted with acondenser for downward distillation, is charged with 5.0 grams of3-betaacetoXy-5,7,9(11)-pregnatrien-20-0ne maleic acid dimethyl esteradduct, 1.72 grams of p-toluenesulfonic acid, and 300 milliliters ofacetic anhydride. Heat is applied and the solution distilled at such arate that about ten to twenty milliliters remain at the end of fourhours. The dark brown residue is cooled to room temperature and water iscarefully added to decompose the remaining acetic anhydride. Threehundred milliliters of water is then added and the mixture extractedwith three one hundred-milliliter portions of ether. The ether phase iswashed with two percent cold sodium bicarbonate solution and with water.

One hundred milliliters of acetone is added to the ether and thesolution treated with Darco activated carbon. The ether is removed byevaporation on the steam bath and water added to the remaining acetonesolution until crystallization begins. Upon cooling and filtration, theyield is 4.1 grams, melting at 108-115 degrees centigrade. After severalrecrystallizations, the melting point becomes constant at 116-119degrees centigrade. The compound also has a second melting point ataround 170 degrees centigrade.

Analysis:

Calculated f0! 0311-14008 C, 68.86; H, 7.46 Found 69.04 7.69 68.71 7 .80

Example 3 In the manner of the preceding examples, the followingcompound was also prepared:

The dimethyl maleate adduct of 3-beta-acetoxy 20 propionoxy5,7,9(l1),l7(20) pregnatetraene having, by infra red spectroscopy, anabsorption peak in the ester region at 1742 cmr characteristic of theC:CO-acyl grouping; and having lost the strong carbonyl absorption at1700 cm. of the starting C-20 ketone.

PREPARATION 18.\IALEI0 ANHYDRIDE ADDUCT 0F 3- BETA-BENzoYLoXY-5,7,9 11)-PREGNATRIEN-20-0NE Seven and one-half grams of the maleic acid adductof 3-beta-hydroxy-5,7,9(11) -pregnatrien- 20-0ne (Preparation 13) wasdissolved in ninety milliliters of pyridine and fifteen milliliters ofbenzoyl chloride was added thereto. The mixture was allowed to standovernight at room Example 4.Maleic anhydride adduct of 3-betabenzoyloxy20 acetomy 5,7,9(11),17(20)- pregnatetraene The maleic anhydride adductof 3-beta-benzoyloxy-5,7,9 (11) -pregnatrien-20-one (5.17 grams), 1.9grams of paratoluenesulfonic acid, and 450 milliliters of aceticanhydride were combined and heated until the acetic anhydride began todistill. The rate of distillation was controlled in such a manner that,after four hours, about ten milliliters of acetic anhydride remained inthe reaction flask. This wa carefully decomposed with 400 milliliters ofwater and the resulting crude solid isolated and crystallized from 300milliliters of alcohol to give 3.73 grams of 3 beta benzoyloxy 20acetoxy 5,7,9(11),17 (20) -pregnatetraene maleic anhydride adduct,melting point -215 degrees centigrade.

In the same manner as given above, other 3,20-diacyloxypregnatetraeneadducts are prepared, including 3,20-dipropionoxy-5,7,9(11),17 (20)-pregnatetraene maleic anhydride adduct, 3- acetoxy,20 propionoxy5,7,9(1l) ,17(20) pregnatetraene maleic anhydride adduct, 3-octanoyloxy20 octanoyloxy 5,7,9(1l),l7(20) pregnatetraene dioctyl maleate adduct,3-benzoyloxy 20 acetoxy 5,7,9(11),l7(20) pregnatetraene diethyl maleateadduct, 3-butyroxy-20- benzoyloxy-5,7,9 (11) ,17 (20) -pregnatetraenemaleic anhydride adduct, 3-formoXy-20-acetoxy- 5,7,9(11) ,17 (20)-pregnatetraene dimethyl maleate adduct,3,20-dibutyroXy-5,7,9(11),l7(20)- piegnatetraene dibutyl maleate adductand the In the same manner as given for the preparation of the anhydrideadducts, the maleimide and N-alkylmaleimide adducts are prepared fromthe corresponding 3-acyloxy-5,7,9 l1) -pregnatrien- 20-one adduct.

It is to be understood that the invention is not to be limited to theexact details of operation or exact compounds shown and described, as0bvious modifications and equivalents will be apparent to one skilled inthe art, and the invention is therefore to be limited only by the scopeof the appended claims.

We claim:

1. A 3,20 diacyloxy-5,7,9(11),1'7(20)-pregnatetraene adduct of theformula:

OAc CH3 AcO wherein Ac is the residue of an unsubstituted organicmonocarboxylic acid containing from one to eight carbon atoms,inclusive; and A is the adduci; radical of a dienophile selected fromthe group consisting of maleic acid anhydride and maleic acid diesterswherein the esterifying group is a lower-alkyl group containing from oneto eight carbon atoms, inclusive.

2. A compound according to claim 1, wherein the 3-acy1oxy group is theacetoxy group.

3. Maleic anhydride adduct of 3,20-diacetoxy- 5,7,9 11) ,17 (20)-pregnatetraene.

4. Maleic anhydride aclduct of 3-benzoy1oxy- 20-acetoxy-5,7,9 (11) ,17(20) -pregnatetraene.

16 5. Dimethyl maieate adduct 01 B-acetoxy-ZO- propionoxy-5,7,9 (11),1'7 (20) -pregnatetraene.

6. Dimethyl maleate adduct of 3,20-diacetoxy- 517,901) ,1? (20)-pregnatetraene.

ROBERT H. LEVIN. A VERN MoINTOSH, JR. GEORGE 8. SPEED.

REFERENCES CITED The following references are of record in the file ofthis patent:

Marshall et a1.: Jour. Am. Chem. Soc., 70, 1837-1839 (1948).

1. A 3.20 - DIACYLOXY-5,7,9(11), 17(20) - PREGNATETRAENE ADDUCT OF THEFORMULA: